1,633 research outputs found
Pyrethroid resistance in southern African Anopheles funestus extends to Likoma Island in Lake Malawi
<p>Abstract</p> <p>Background</p> <p>A mosquito survey was carried out on the island of Likoma in Lake Malawi with a view to collecting baseline data to determine the feasibility of implementing an integrated malaria vector control programme. No vector control interventions are currently being applied on the island apart from the sporadic use of treated and untreated bed nets.</p> <p>Results</p> <p>Large numbers of <it>Anopheles funestus </it>were found resting inside houses. WHO susceptibility tests were carried out on wild caught females and 1-5 day old F-1 female progeny. Wild caught females were tested on deltamethrin (77.8% mortality) and bendiocarb (56.4% mortality). Female progeny were tested on deltamethrin (41.4% mortality), permethrin (40.4%), bendiocarb (52.5%), propoxur (7.4%), malathion, fenitrothion, DDT, dieldrin (all 100%) and pirimiphos-methyl (98.9%). The malaria parasite rate was 4.9%. A small number of <it>Anopheles arabiensis </it>were also collected.</p> <p>Conclusion</p> <p>This locality is 1,500 km north of the currently known distribution of pyrethroid resistant <it>An. funestus </it>in southern Africa. The susceptibility results mirror those found in southern Mozambique and South African populations, but are markedly different to <it>An. funestus </it>populations in Uganda, indicating that the Malawi resistance has spread from the south.</p
Helicobacter pylori eradication therapy to prevent gastric cancer in healthy asymptomatic infected individuals: systematic review and meta-analysis of randomised controlled trials
OBJECTIVES: To determine whether searching for Helicobacter pylori and treating with eradication therapy leads to a reduction in incidence of gastric cancer among healthy asymptomatic infected individuals. DESIGN: Systematic review and meta-analysis of randomised controlled trials. DATA SOURCES: Medline, Embase, and the Cochrane central register of controlled trials were searched through to December 2013. Conference proceedings between 2001 and 2013 were hand searched. A recursive search was performed with bibliographies of relevant studies. There were no language restrictions. ELIGIBILITY CRITERIA FOR SELECTING STUDIES: Randomised controlled trials examining the effect of at least seven days of eradication therapy on subsequent occurrence of gastric cancer in adults who tested positive for Helicobacter pylori but otherwise healthy and asymptomatic were eligible. The control arm had to receive placebo or no treatment. Subjects had to be followed for â„ 2 years. MAIN OUTCOME MEASURES: Primary outcome, defined a priori, was the effect of eradication therapy on the subsequent occurrence of gastric cancer expressed as a relative risk of gastric cancer with 95% confidence intervals. RESULTS: The search strategy identified 1560 citations, of which six individual randomised controlled trials were eligible. Fifty one (1.6%) gastric cancers occurred among 3294 individuals who received eradication therapy versus 76 (2.4%) in 3203 control subjects (relative risk 0.66, 95% confidence interval 0.46 to 0.95), with no heterogeneity between studies (I(2)=0%, P=0.60). If the benefit of eradication therapy was assumed to persist lifelong the number needed to treat was as low as 15 for Chinese men and as high as 245 for US women. CONCLUSIONS: These data provide limited, moderate quality evidence that searching for and eradicating H pylori reduces the incidence of gastric cancer in healthy asymptomatic infected Asian individuals, but these data cannot necessarily be extrapolated to other populations
Do patients with non-ulcer dyspepsia respond differently to Helicobacter pylori eradication treatments from those with peptic ulcer disease? A systematic review
Aim: It is controversial whether patients with non-ulcer dyspepsia (NUD) respond differently to Helicobacter pylori (H pylori) eradication treatment than those with peptic ulcer disease (PUD). To review the evidence for any difference in H pylori eradication rates between PUD and NUD patients. Methods: A literature search for full articles and meeting abstracts to July 2004 was conducted. We included studies evaluating the efficacy of a proton pump inhibitor (P) or ranitidine bismuth citrate (RBC) plus two antibiotics of clarithromycin (C), amoxicillin (A), metronidazole (M), or P-based quadruple therapies for eradicating the infection. Results: Twenty-two studies met the criteria. No significant difference in eradication rates was found between PUD and NUD patients when treated with 7-d RBCCA, 10-d PCA or P-based quadruple therapies. When the 7-d PCA was used, the pooled H pylori eradication rate was 82.1% (431/525) and 72.6% (448/617) for PUD and NUD patients, respectively, yielding a RR of 1.15 (95%CI 1.01-1.29). However, the statistically significant difference was seen only in meeting abstracts, but not in full publications. Conclusion: There is no convincing evidence to suggest that NUD patients respond to H pylori eradication treatments differently from those with PUD, although a trend exists with the 7-d PCA therapy. © 2005 The WJG Press and Elsevier Inc. All rights reserved.published_or_final_versio
Cooperation, collective action, and the archeology of large-scale societies
Archeologists investigating the emergence of large-scale societies in the past have renewed interest in examining the dynamics of cooperation as a means of understanding societal change and organizational variability within human groups over time. Unlike earlier approaches to these issues, which used models designated voluntaristic or managerial, contemporary research articulates more explicitly with frameworks for cooperation and collective action used in other fields, thereby facilitating empirical testing through better definition of the costs, benefits, and social mechanisms associated with success or failure in coordinated group action. Current scholarship is nevertheless bifurcated along lines of epistemology and scale, which is understandable but problematic for forging a broader, more transdisciplinary field of cooperation studies. Here, we point to some areas of potential overlap by reviewing archeological research that places the dynamics of social cooperation and competition in the foreground of the emergence of large-scale societies, which we define as those having larger populations, greater concentrations of political power, and higher degrees of social inequality. We focus on key issues involving the communal-resource management of subsistence and other economic goods, as well as the revenue flows that undergird political institutions. Drawing on archeological cases from across the globe, with greater detail from our area of expertise in Mesoamerica, we offer suggestions for strengthening analytical methods and generating more transdisciplinary research programs that address human societies across scalar and temporal spectra
The cuttlefish Sepia officinalis (Sepiidae, Cephalopoda) constructs cuttlebone from a liquid-crystal precursor
Cuttlebone, the sophisticated buoyancy device of cuttlefish, is made of extensive superposed chambers that have a complex internal arrangement of calcified pillars and organic membranes. It has not been clear how this structure is assembled. We find that the membranes result from a myriad of minor membranes initially filling the whole chamber, made of nanofibres evenly oriented within each membrane and slightly rotated with respect to those of adjacent membranes, producing a helical arrangement. We propose that the organism secretes a chitin-protein complex, which self-organizes layer-by-layer as a cholesteric liquid crystal, whereas the pillars are made by viscous fingering. The liquid crystallization mechanism permits us to homologize the elements of the cuttlebone with those of other coleoids and with the nacreous septa and the shells of nautiloids. These results challenge our view of this ultra-light natural material possessing desirable mechanical, structural and biological properties, suggesting that two self-organizing physical principles suffice to understand its formation.Spanish Ministerio de Ciencia e Innovacion [CGL2010-20748-CO2-01, CGL2013-48247-P, FIS2013-48444-C2-2-P]; Andalusian Consejeria de Innovacion Ciencia y Tecnologia [RNM6433]; (Sepiatech, PROMAR program) of the Portuguese Ministerio da Agricultura e do Mar, Portugal [31.03.05.FEP.002]; Junta de Andalucia [RNM363]; FP7 COST Action of the European Community. [TD0903]info:eu-repo/semantics/publishedVersio
Novel Approaches to Inhibition of Gastric Acid Secretion
The gastric H,K-adenosine triphosphatase (ATPase) is the primary target for treatment of acid-related diseases. Proton pump inhibitors (PPIs) are weak bases composed of two moieties, a substituted pyridine with a primary pKa of about 4.0 that allows selective accumulation in the secretory canaliculus of the parietal cell, and a benzimidazole with a second pKa of about 1.0. Protonation of this benzimidazole activates these prodrugs, converting them to sulfenic acids and/or sulfenamides that react covalently with one or more cysteines accessible from the luminal surface of the ATPase. The maximal pharmacodynamic effect of PPIs as a group relies on cyclic adenosine monophosphateâdriven H,K-ATPase translocation from the cytoplasm to the canalicular membrane of the parietal cell. At present, this effect can only be achieved with protein meal stimulation. Because of covalent binding, inhibitory effects last much longer than their plasma half-life. However, the short dwell-time of the drug in the blood and the requirement for acid activation impair their efficacy in acid suppression, particularly at night. All PPIs give excellent healing of peptic ulcer and produce good, but less than satisfactory, results in reflux esophagitis. PPIs combined with antibiotics eradicate Helicobacter pylori, but success has fallen to less than 80%. Longer dwell-time PPIs promise to improve acid suppression and hence clinical outcome. Potassium-competitive acid blockers (P-CABs) are another class of ATPase inhibitors, and at least one is in development. The P-CAB under development has a long duration of action even though its binding is not covalent. PPIs with a longer dwell time or P-CABs with long duration promise to address unmet clinical needs arising from an inability to inhibit nighttime acid secretion, with continued symptoms, delayed healing, and growth suppression of H. pylori reducing susceptibility to clarithromycin and amoxicillin. Thus, novel and more effective suppression of acid secretion would benefit those who suffer from acid-related morbidity, continuing esophageal damage and pain, nonsteroidal anti-inflammatory drugâinduced ulcers, and nonresponders to H. pylori eradication
Doppler broadening of in-flight positron annihilation radiation due to electron momentum
An overview is given on the first observation of Doppler broadening due to electron momentum in the Ï rays emitted from in-flight two-photon annihilation when highly energetic positrons traverse thin foils. This observation can serve as basis in the development of a new probe of electron momentum distributions similar to Compton or electron scattering technique
Erratum: Doppler broadening of in-flight positron annihilation radiation due to electron momentum (Phys. Rev. Lett. (2001) 86 (5612))
Elementary Forms of the Metaphorical Life : Tropes at Work in Durkheimâs Theory of the Religious
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Full recovery of a 13-year-old boy with pediatric Ramsay Hunt syndrome using a shorter course of aciclovir and steroid at lower doses: a case report
<p>Abstract</p> <p>Introduction</p> <p>Reports on children with Ramsay Hunt syndrome are limited in the literature, resulting in uncertainty regarding the clinical manifestations and outcome of this syndrome. Treatment for Ramsay Hunt syndrome is usually with antivirals, although there is no evidence for beneficial effect on the outcome of Ramsay Hunt syndrome in adults (insufficient data on children exists). Here, we report a case of Ramsay Hunt syndrome occurring in a child who inadvertently received a lower dose of aciclovir and steroid administered for shorter than is usual. Our patient made a full recovery.</p> <p>Case presentation</p> <p>A 13-year-old African boy presented to our out-patients department with an inability to move the right side of his face for one week. He had previously been seen by the doctor on call, who prescribed aciclovir 200 mg three times per day and prednisone 20 mg once daily, both orally for five days, with a working diagnosis of Bell's palsy. After commencement of aciclovir-prednisone, while at home, our patient had headache, malaise, altered taste, vomiting after feeds, a ringing sound in his right ear as well as earache and ear itchiness. Additionally, he developed numerous fluid-filled pimples on his right ear. On presentation, a physical examination revealed a right-sided lower motor neuron facial nerve palsy and a healing rash on the right pinna. On direct questioning, our patient admitted having had chicken pox about three months previously. Based on the history and physical examination, Ramsay Hunt syndrome was diagnosed. Our patient was lost to follow-up until 11 months after the onset of illness; at this time, his facial nerve function was normal.</p> <p>Conclusions</p> <p>This case report documents the clinical manifestations and outcome of pediatric Ramsay Hunt syndrome; a condition with few case reports in the literature. In addition, our patient made a full recovery despite inadvertently receiving a lower dose of aciclovir and steroid administered for shorter than is usual.</p
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